Well do you know if you have good sea legs, not likely to be see sick nothing worse than 10/14 days of this.
Why not try a short cruise [3/4 days] some available from the UK to see whether you like it.
In general cruising is like staying in a floating 4/5 star hotel with far more amenities immediately to hand. [Swimming pool; hairdresser; casino; entertainment every night; saunas; whirlpools; several bars to drink in; lots of eating opportunities 24 hours a day]
It is a cashless society everything is charged to your stateroom/cabin account you only need money when you go ashore. Nearly all ships use the US dollar. On some cruises you go to sleep leaving one port and waken up somewhere new one !!
Well hope this gives a brief flavour on some of the things you will see and do if you ever did cruise.
What exactly do you want us to help you with? It's a bit difficult to help you without having any idea of what you want to know.
I went on a Meditearranean cruise &, although at the time I suffered terribly with travel sickness in cars, coaches & trains, I didn't suffer at all on the ship! However my parents went last year and apparantly the majority of passengers were ill on the first night, my parents had to have an injection from the onboard doctor! But after that they were fine. I think it depends where your ship departs from, and I suppose how well you cope with travelling in general.
Go to the travel agent. Get yourself some Cruise brochures. Sit down and read through them. You will have a lot more knowledge of cruising when you have finished than before you began! Happy cruising.
Buy a copy of the Berlitz Guide to Cruising and Cruise Ships. You will find it most useful.